[Solved] -[__NSCFDictionary objectAtIndex:]: unrecognized selector sent to instance [duplicate]

NSArray *retrievedJTrans = [NSJSONSerialization JSONObjectWithData:response options:0 error:&jsonParsingError];

is a dictionary

what you might want

NSDictionary *retrievedJTransD = [NSJSONSerialization JSONObjectWithData:response options:0 error:&jsonParsingError];
NSArray *retrievedJTrans = retrievedJTransD[@"data"][@"translations"];